The design, development, and evaluation of an experimental translation system that aims to aid transactions between a deaf person and a clerk in a post office (PO) is described. The system uses a speech recognizer to recognize speech from a PO clerk and then synthesizes recognized phrases in British Sign language (BSL) using a specially developed avatar. The main objective in developing this prototype system was to determine how useful it would be to a customer whose first language was BSL, and to discover what areas of the system required more research and development to make it more effective. The system was evaluated by 6 prelingually profoundly deaf people and 3 PO clerks. Deaf users and PO clerks were supportive of the system, but the former group required a higher quality of signing from the avatar and the latter a system that was less constrained in the phrases it could recognize; both these areas are being addressed in the next phase of development.